2020 European guideline for the diagnosis and treatment of gonorrhoea in adults

The novel 2024 WHO Neisseria gonorrhoeae reference strains for global quality assurance of laboratory investigations and superseded WHO N. gonorrhoeae reference strains-phenotypic, genetic and reference genome characterization

OBJECTIVES

MDR and XDR Neisseria gonorrhoeae strains remain major public health concerns internationally, and quality-assured global gonococcal antimicrobial resistance (AMR) surveillance is imperative. The WHO global Gonococcal Antimicrobial Surveillance Programme (GASP) and WHO Enhanced GASP (EGASP), including metadata and WGS, are expanding internationally. We present the phenotypic, genetic and reference genome characteristics of the 2024 WHO gonococcal reference strains (n = 15) for quality assurance worldwide. All superseded WHO gonococcal reference strains (n = 14) were identically characterized.

MATERIAL AND METHODS

The 2024 WHO reference strains include 11 of the 2016 WHO reference strains, which were further characterized, and four novel strains. The superseded WHO reference strains include 11 WHO reference strains previously unpublished. All strains were characterized phenotypically and genomically (single-molecule PacBio or Oxford Nanopore and Illumina sequencing).

RESULTS

The 2024 WHO reference strains represent all available susceptible and resistant phenotypes and genotypes for antimicrobials currently and previously used (n = 22), or considered for future use (n = 3) in gonorrhoea treatment. The novel WHO strains include internationally spreading ceftriaxone resistance, ceftriaxone resistance due to new penA mutations, ceftriaxone plus high-level azithromycin resistance and azithromycin resistance due to mosaic MtrRCDE efflux pump. AMR, serogroup, prolyliminopeptidase, genetic AMR determinants, plasmid types, molecular epidemiological types and reference genome characteristics are presented for all strains.

CONCLUSIONS

The 2024 WHO gonococcal reference strains are recommended for internal and external quality assurance in laboratory examinations, especially in the WHO GASP, EGASP and other GASPs, but also in phenotypic and molecular diagnostics, AMR prediction, pharmacodynamics, epidemiology, research and as complete reference genomes in WGS analysis.

Managing treatment failure in Neisseria gonorrhoeae infection: current guidelines and future directions

Due to the continued emergence of resistance to extended-spectrum cephalosporin antibiotics, clinicians are increasingly more likely to encounter cases of Neisseria gonorrhoeae treatment failure. The current international treatment guidelines offer few regimens for cases of N gonorrhoeae infection that do not respond to first-line therapy, and there are many complexities that should be considered with such regimens; these include regional variations in resistance to alternative agents, access to different antibiotics, and penetration of those antibiotics within different tissues. Further, such regimens do not account for the challenges of treating pharyngeal infections; many patients who have not responded to treatment with extended-spectrum cephalosporin antibiotics to date have had pharyngeal involvement. In addition, pharyngeal infections play a pivotal role in the emergence and spread of antimicrobial resistance in N gonorrhoeae and are more difficult to treat than urogenital infections because of the unfavourable pharmacokinetics of cephalosporins in pharyngeal tissues. Here, we summarise the current guidelines, provide additional approaches and considerations for clinicians, and highlight knowledge gaps that should be addressed to ensure appropriate therapy in cases of treatment failure.

Gonorrhoea treatment guideline compliance and influence factors in Guangdong province, China: a cross-sectional survey

BACKGROUND

The indiscriminate use of antibiotics has accelerated antimicrobial resistance (AMR) in Neisseria gonorrhoeae (NG), emphasising the need to follow treatment guidelines. This study aimed to assess the rate of adherence to standard treatment among patients with gonorrhoea and identify influencing factors.

METHODS

A survey was conducted in Guangdong province, China, involving uncomplicated gonorrhoea cases registered in the Chinese Information System for Disease Control and Prevention. Data on demographic characteristics and medical information were collected to determine the standard treatment rate, defined as the proportion of patients receiving treatment according to national guidelines (ie, a single dose of ceftriaxone 250 mg, spectinomycin 2 g, cefotaxime 1 g or other third-generation cephalosporins). Medication choices were documented. χ² tests and multilevel logistic regression were used to analyse factors associated with standard treatment.

RESULTS

The survey included 2424 patients with gonorrhoea from 59 hospitals. The standard treatment rate was 30.7% (743/2424), with 36.2% for females and 29.6% for males. Common reasons for substandard treatment included the use of non-guideline medications (42.3%, 710/1681) and incorrect dosing (36.2%, 605/1681). Factors associated with the standard treatment rate included gender, address, educational level, department, physicians' training, number of diagnosed gonorrhoea cases and hospital level.

CONCLUSION

The standard treatment rate for gonorrhoea in Guangdong province, China, is below expectations. Comprehensive measures, such as establishing a goal-directed monitoring system and implementing promotional activities, are needed to improve adherence to treatment guidelines.

Antimicrobial treatment and resistance in sexually transmitted bacterial infections

Sexually transmitted infections (STIs) have been part of human life since ancient times, and their symptoms affect quality of life, and sequelae are common. Socioeconomic and behavioural trends affect the prevalence of STIs, but the discovery of antimicrobials gave hope for treatment, control of the spread of infection and lower rates of sequelae. This has to some extent been achieved, but increasing antimicrobial resistance and increasing transmission in high-risk sexual networks threaten this progress. For Neisseria gonorrhoeae, the only remaining first-line treatment (with ceftriaxone) is at risk of becoming ineffective, and for Mycoplasma genitalium, for which fewer alternative antimicrobial classes are available, incurable infections have already been reported. For Chlamydia trachomatis, in vitro resistance to first-line tetracyclines and macrolides has never been confirmed despite decades of treatment of this highly prevalent STI. Similarly, Treponema pallidum, the cause of syphilis, has remained susceptible to first-line penicillin.

Management of Neisseria gonorrhoeae infection: from drug resistance to drug repurposing

INTRODUCTION

Neisseria gonorrhoeae is a common sexually transmitted disease connected with extensive drug resistance to many antibiotics. Presently, only expanded spectrum cephalosporins (ceftriaxone and cefixime) and azithromycin remain useful for its management.

AREAS COVERED

New chemotypes for the classical antibiotic drug target gyrase/topoisomerase IV afforded inhibitors with potent binding to these enzymes, with an inhibition mechanism distinct from that of fluoroquinolones, and thus less prone to mutations. The α-carbonic anhydrase from the genome of this bacterium (NgCAα) was also validated as an antibacterial target.

EXPERT OPINION

By exploiting different subunits from the gyrase/topoisomerase IV as well as new chemotypes, two new antibiotics reached Phase II/III clinical trials, zoliflodacin and gepotidacin. They possess a novel inhibition mechanism, binding in distinct parts of the enzyme compared to the fluoroquinolones. Other chemotypes with inhibitory activity in these enzymes were also reported. NgCAα inhibitors belonging to a variety of classes were obtained, with several sulfonamides showing MIC values in the range of 0.25-4 µg/mL and significant activity in animal models of this infection. Acetazolamide and similar CA inhibitors might thus be repurposed as antiinfectives. The scientific/patent literature has been searched for on PubMed, ScienceDirect, Espacenet, and PatentGuru, from 2016 to 2024.

Self-sampling with oral rinse to detect oropharyngeal Neisseria gonorrhoeae among men who have sex with men: results from an exploratory study in Belgium (the SSONG Study)

OBJECTIVES

We aimed to assess whether a self-collected oral rinse was non-inferior to clinician-collected oropharyngeal swabs to detect Neisseria gonorrhoeae (Ng) using culture and nucleic acid amplification tests (NAAT) among men who have sex with men (MSM), and whether Ng may still be detected in oral rinses for a minimum of 5 days after collection.

METHODS

MSM with a positive Ng result in an oropharyngeal or pooled sample (oropharynx, urethra and anorectum) were approached. Clinician-collected oropharyngeal swabs and oral rinses (15 mL sterile water) were taken. Ng culture and NAAT (Abbott 2000m RealTime System CT/NG assay and in-house PCR) were performed. Diagnostic accuracy was assessed using sensitivity and specificity, and agreement between both techniques using Cohen's kappa statistic. Aliquots of positive oral rinses were left at room temperature for a minimum of 5 days and reanalysed using NAAT. Lastly, participants filled in a questionnaire to explore perceptions of both methods.

RESULTS

We included 100 participants between June 2022 and October 2023. 45 individuals (45 of 100) had a positive Ng result in either the oral rinses (42 of 45, 93%) or the swabs (36 of 45, 80%). Sensitivity was higher for oral rinses than swabs (sensitivity=0.93/0.80, specificity=1.0/1.0, respectively) and agreement between both techniques was good (kappa=0.75, p<0.001). Of the 42 positive oral rinses, 37 remained positive after a minimum of 5 days (88.1%). Using culture, 18 individuals had a positive Ng result in either the oral rinses (8 of 18, 44%) or the swabs (16 of 18, 88%). Most participants found the oral rinse easy or very easy to use and would be willing to use the oral rinse for home-based sampling.

CONCLUSION

We detected more oropharyngeal Ng infections via NAAT using oral rinses than swab samples. However, swabs were better than oral rinses for culturing Ng. Oral rinses might allow for home-based self-sampling to detect oropharyngeal Ng.

Recent dynamics in Neisseria gonorrhoeae genomic epidemiology in Brazil: antimicrobial resistance and genomic lineages in 2017-20 compared to 2015-16

OBJECTIVES

Regular quality-assured WGS with antimicrobial resistance (AMR) and epidemiological data of patients is imperative to elucidate the shifting gonorrhoea epidemiology, nationally and internationally. We describe the dynamics of the gonococcal population in 11 cities in Brazil between 2017 and 2020 and elucidate emerging and disappearing gonococcal lineages associated with AMR, compare to Brazilian WGS and AMR data from 2015 to 2016, and explain recent changes in gonococcal AMR and gonorrhoea epidemiology.

METHODS

WGS was performed using Illumina NextSeq 550 and genomes of 623 gonococcal isolates were used for downstream analysis. Molecular typing and AMR determinants were obtained and links between genomic lineages and AMR (determined by agar dilution/Etest) examined.

RESULTS

Azithromycin resistance (15.6%, 97/623) had substantially increased and was mainly explained by clonal expansions of strains with 23S rRNA C2611T (mostly NG-STAR CC124) and mtr mosaics (mostly NG-STAR CC63, MLST ST9363). Resistance to ceftriaxone and cefixime remained at the same levels as in 2015-16, i.e. at 0% and 0.2% (1/623), respectively. Regarding novel gonorrhoea treatments, no known zoliflodacin-resistance gyrB mutations or gepotidacin-resistance gyrA mutations were found. Genomic lineages and sublineages showed a phylogenomic shift from sublineage A5 to sublineages A1-A4, while isolates within lineage B remained diverse in Brazil.

CONCLUSIONS

Azithromycin resistance, mainly caused by 23S rRNA C2611T and mtrD mosaics/semi-mosaics, had substantially increased in Brazil. This mostly low-level azithromycin resistance may threaten the recommended ceftriaxone-azithromycin therapy, but the lack of ceftriaxone resistance is encouraging. Enhanced gonococcal AMR surveillance, including WGS, is imperative in Brazil and other Latin American and Caribbean countries.

Antimicrobial-resistant Neisseria gonorrhoeae in Europe in 2020 compared with in 2013 and 2018: a retrospective genomic surveillance study

BACKGROUND

Regular quality-assured whole-genome sequencing linked to antimicrobial resistance (AMR) and patient metadata is imperative to elucidate the shifting gonorrhoea epidemiology, both nationally and internationally. We aimed to examine the gonococcal population in the European Economic Area (EEA) in 2020, elucidate emerging and disappearing gonococcal lineages associated with AMR and patient metadata, compare with 2013 and 2018 whole-genome sequencing data, and explain changes in gonococcal AMR and gonorrhoea epidemiology.

METHODS

In this retrospective genomic surveillance study, we analysed consecutive gonococcal isolates that were collected in EEA countries through the European Gonococcal Antimicrobial Surveillance Programme (Euro-GASP) in 2020, and made comparisons with Euro-GASP data from 2013 and 2018. All isolates had linked AMR data (based on minimum inhibitory concentration determination) and patient metadata. We performed whole-genome sequencing and molecular typing and AMR determinants were derived from quality-checked whole-genome sequencing data. Links between genomic lineages, AMR, and patient metadata were examined.

FINDINGS

1932 gonococcal isolates collected in 2020 in 21 EEA countries were included. The majority (81·2%, 147 of 181 isolates) of azithromycin resistance (present in 9·4%, 181 of 1932) was explained by the continued expansion of the Neisseria gonorrhoeae sequence typing for antimicrobial resistance (NG-STAR) clonal complexes (CCs) 63, 168, and 213 (with mtrD/mtrR promoter mosaic 2) and the novel NG-STAR CC1031 (semi-mosaic mtrD variant 13), associated with men who have sex with men and anorectal or oropharyngeal infections. The declining cefixime resistance (0·5%, nine of 1932) and negligible ceftriaxone resistance (0·1%, one of 1932) was largely because of the progressive disappearance of NG-STAR CC90 (with mosaic penA allele), which was predominant in 2013. No known resistance determinants for novel antimicrobials (zoliflodacin, gepotidacin, and lefamulin) were found.

INTERPRETATION

Azithromycin-resistant clones, mainly with mtrD mosaic or semi-mosaic variants, appear to be stabilising at a relatively high level in the EEA. This mostly low-level azithromycin resistance might threaten the recommended ceftriaxone-azithromycin therapy, but the negligible ceftriaxone resistance is encouraging. The decreased genomic population diversity and increased clonality could be explained in part by the COVID-19 pandemic resulting in lower importation of novel strains into Europe.

FUNDING

European Centre for Disease Prevention and Control and Örebro University Hospital.

High cure rates of Mycoplasma genitalium following empiric treatment with azithromycin alongside frequent detection of macrolide resistance in Austria

BACKGROUND

Mycoplasma genitalium (MG) is an emerging sexually transmitted infection, often harboring resistance-associated mutations to azithromycin (AZM). Global surveillance has been mandated to tackle the burden caused by MG, yet no data are available for Austria. Thus, we aimed to investigate the prevalence of MG, disease characteristics, and treatment outcomes at the largest Austrian HIV-and STI clinic.

METHODS

All MG test results at the Medical University of Vienna from 02/2019 to 03/2022 were evaluated. Azithromycin resistance testing was implemented in 03/2021.

RESULTS

Among 2671 MG tests, 199 distinct and mostly asymptomatic (68%; 135/199) MG infections were identified, affecting 10% (178/1775) of all individuals. This study included 83% (1479/1775) men, 53% (940/1775) men who have sex with men (MSM), 31% (540/1754) HIV+, and 15% (267/1775) who were using HIV pre-exposure prophylaxis (PrEP). In logistic regression analysis, 'MSM' (aOR 2.55 (95% CI 1.65-3.92)), 'use of PrEP' (aOR 2.29 (95% CI 1.58-3.32)), and 'history of syphilis' (aOR 1.57 (95% CI 1.01-2.24) were independent predictors for MG infections. Eighty-nine percent (178/199) received treatment: 11% (21/178) doxycycline (2 weeks), 52% (92/178) AZM (5 days), and 37% ( 65/178) moxifloxacin (7-10 days) and 60% (106/178) had follow-up data available showing negative tests in 63% (5/8), 76% (44/58) and 85% (34/40), respectively. AZM resistance analysis was available for 57% (114/199)) and detected in 68% (78/114). Resistance-guided therapy achieved a cure in 87% (53/61), yet, empiric AZM-treatment (prior to 03/2021) cleared 68% (26/38).

CONCLUSIONS

Mycoplasma genitalium was readily detected in this Austrian observational study, affected predominantly MSM and often presented as asymptomatic disease. We observed a worryingly high prevalence of AZM resistance mutations; however, empiric AZM treatment cleared twice as many MG infections as expected.

Orogenital and anal infection by Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, and other sexually transmitted infections in men who have sex with men in Lisbon

BACKGROUND

Men who have sex with men (MSM) are at risk for sexually transmitted infections (STIs), but more data on extragenital carriage are needed.

AIM

We assessed the genital and extragenital prevalence of bacterial and other STIs in MSM in a Lisbon sexual health clinic.

METHODS

We screened oral, anal, and urine samples of MSM visiting the GAT-CheckpointLX clinic June 2017-December 2021 for Chlamydia trachomatis (including lymphogranuloma venereum, LGV), Neisseria gonorrhoeae, Mycoplasma genitalium, Trichomonas vaginalis, Mycoplasma hominis, Ureaplasma urealyticum, and U. parvum. Ano-oro-genital lesions were tested for LGV, Treponema pallidum, and Herpes Simplex Virus. Blood was tested for HIV and T. pallidum antibodies.

RESULTS

N. gonorrhoeae was found in 16.6% of the MSM followed by C. trachomatis (13.2%), M. genitalium (10.3%) and T. vaginalis (0.2%). The most frequent occurrence was anorectal (C. trachomatis, M. genitalium) and oral (N. gonorrhoeae). We found high carriage of U. urealyticum (36.1%) and M. hominis (22.1%). LGV was detected in 21.8% of chlamydia-positive anorectal swabs. Syphilis was detected in 22.6% of tested MSM, while 13.8% had HIV. Gonorrhoea and chlamydia were significantly more prevalent in MSM with concomitant HIV or syphilis.

CONCLUSION

The substantial extragenital prevalence of bacterial STIs in MSM, and HIV and syphilis coinfections, suggest screening has value in identifying hidden carriage and in contributing for providing better care.

Single-dose cefixime 800 mg plus doxycycline 100 mg twice a day for 7 days compared with single-dose ceftriaxone 1 g plus single-dose azithromycin 2 g for treatment of urogenital, rectal, and pharyngeal gonorrhoea: a randomised clinical trial

OBJECTIVES

To evaluate the efficacy and tolerability of a single dose of oral cefixime 800 mg plus oral doxycycline 100 mg twice a day for 7 days, compared with a recommended single dose of ceftriaxone plus single dose of oral azithromycin, for treatment of uncomplicated urogenital, rectal, or pharyngeal gonorrhoea.

METHODS

A noninferiority, open-label, multicentre randomized controlled trial was conducted in Prague, Czech Republic. Some 161 patients, 18-65 years of age diagnosed with uncomplicated urogenital, rectal, or pharyngeal gonorrhoea by nucleic acid amplification test (NAAT) were randomized to treatment with single dose of cefixime 800 mg plus doxycycline 100 mg twice a day for 1 week or a single dose of ceftriaxone 1 g intramuscularly plus single dose of azithromycin 2 g. The primary outcome was the number of participants with negative culture and NAAT at 1 week and 3 weeks, respectively, after treatment initiation.

RESULTS

In all, 161 patients were randomized and 152 were included in per-protocol analyses. All 76 (100%; 95% CI, 0.95-1.00) patients treated with ceftriaxone plus azithromycin achieved negative cultures and NAAT after treatment. In the cefixime plus doxycycline arm at week 1, culture was negative in all 76 (100%) patients; at week 3, culture was negative in 70 of the 76 patients (92%; 95% CI, 0.84-0.97) and NAAT negative in 66 of the 76 patients (87%; 95% CI, 0.77-0.94). At week 3, culture and NAAT were negative in 65 of the 76 patients (86%; 95% CI, 0.76-0.93). Per-protocol risk difference was 14.5%; 95% CI, 6.56-22.38. All treatment failures observed in the cefixime arm were pharyngeal gonorrhoea cases.

DISCUSSION

The combination of cefixime and doxycycline did not achieve noninferiority to ceftriaxone and azithromycin for treatment of gonorrhoea when including pharyngeal gonorrhoea. It did, however, show high efficacy for urogenital and rectal gonorrhoea.

STI pathogens in the oropharynx: update on screening and treatment

PURPOSE OF REVIEW

The rise in antimicrobial resistance in several STI pathogens such as Neisseria gonorrhoeae has become a public health threat as only one first-line treatment remains. Reducing screening interval for gonorrhoea and chlamydia in high-prevalence populations has been proposed to address antimicrobial stewardship, but this remains controversial. This review aimed to revisit the epidemiology of infections at the oropharynx and review the current screening recommendations and treatment guidelines in different populations.

RECENT FINDINGS

Emerging evidence suggests that the oropharynx is the primary anatomical site for gonorrhoea transmission but maybe not for chlamydia transmission. Most international guidelines recommend 3-monthly oropharyngeal gonorrhoea and chlamydia screening for high-prevalence populations (e.g. men who have sex with men) but not low-prevalence populations (e.g. heterosexuals) given the clinical and public health benefits of screening in low-prevalence populations are still unclear. Doxycycline remains the first-line treatment for oropharyngeal chlamydia in most guidelines. However, some countries have moved from dual therapy (ceftriaxone and azithromycin) to monotherapy (ceftriaxone) for oropharyngeal gonorrhoea treatment to address antimicrobial stewardship.

SUMMARY

The transmission of gonorrhoea and chlamydia is still not fully understood. Further work will be required to evaluate the benefits and harms of reducing screening in high-prevalence populations.

Evaluating the efficacy of different antibiotics against Neisseria gonorrhoeae: a pharmacokinetic/pharmacodynamic analysis using Monte Carlo simulation

BACKGROUND

With the widespread use of antibiotics, antimicrobial resistance in Neisseria gonorrhoeae is worsening. The objective of this study was to evaluate the efficacy changes of seven antibiotics in the treatment of N. gonorrhoeae by using Monte Carlo simulation combined with pharmacokinetics/pharmacodynamics/ (PK/PD).

METHODS

The minimum inhibitory concentration (MIC) of antibiotics against clinical isolates from 2013 to 2020 in Nanjing, China, was determined by agar dilution method. The probability of target attainment (PTA) was estimated at each MIC value and the cumulative fraction of response (CFR) was calculated to evaluate the efficacy of these regimens.

RESULTS

All dosage regimens of seven antibiotics achieved PTAs ≥ 90% for MIC ≤ 0.06 µg/ml. But when the MIC was increased to 1 µg/ml, PTAs at each MIC value exceeded 90% only for ceftriaxone 1,000 mg and 2,000 mg, zoliflodacin 2,000 mg and 3,000 mg. Among them, the CFR values of each dosing regimen against N. gonorrhoeae only for ceftriaxone, cefixime and zoliflodacin were ≥ 90% in Nanjing from 2013 to 2020.

CONCLUSIONS

Cephalosporins are still the first-line drugs in the treatment of gonorrhea. However, the elevated MIC values of cephalosporins can lead to decline in clinical efficacy of the conventional dose regimens, and increasing the dose of ceftriaxone to 1,000 mg-2,000 mg may improve the efficacy. In addition, zoliflodacin is possible to be a potential therapeutic agent in the future.

Pharmacodynamics of zoliflodacin plus doxycycline combination therapy against Neisseria gonorrhoeae in a gonococcal hollow-fiber infection model

Antimicrobial resistance in the sexually transmitted bacterium Neisseria gonorrhoeae is compromising the management and control of gonorrhea globally. Optimized use and enhanced stewardship of current antimicrobials and development of novel antimicrobials are imperative. The first in class zoliflodacin (spiropyrimidinetrione, DNA Gyrase B inhibitor) is a promising novel antimicrobial in late-stage clinical development for gonorrhea treatment, i.e., the phase III randomized controlled clinical trial (ClinicalTrials.gov Identifier: NCT03959527) was recently finalized, and zoliflodacin showed non-inferiority compared to the recommended ceftriaxone plus azithromycin dual therapy. Doxycycline, the first-line treatment for chlamydia and empiric treatment for non-gonococcal urethritis, will be frequently given together with zoliflodacin because gonorrhea and chlamydia coinfections are common. In a previous static in vitro study, it was indicated that doxycycline/tetracycline inhibited the gonococcal killing of zoliflodacin in 6-h time-kill curve analysis. In this study, our dynamic in vitro hollow-fiber infection model (HFIM) was used to investigate combination therapies with zoliflodacin and doxycycline. Dose-range experiments using the three gonococcal strains WHO F (susceptible to relevant therapeutic antimicrobials), WHO X (extensively drug-resistant, including ceftriaxone-resistant; zoliflodacin-susceptible), and SE600/18 (zoliflodacin-susceptible strain with GyrB S467N substitution) were conducted simulating combination therapy with a single oral dose of zoliflodacin 0.5-4 g combined with a doxycycline daily oral dose of 200 mg administered as 100 mg twice a day, for 7 days (standard dose for chlamydia treatment). Comparing combination therapy of zoliflodacin (0.5-4 g single dose) plus doxycycline (200 mg divided into 100 mg twice a day orally, for 7 days) to zoliflodacin monotherapy (0.5-4 g single dose) showed that combination therapy was slightly more effective than monotherapy in the killing of N. gonorrhoeae and suppressing emergence of zoliflodacin resistance. Accordingly, WHO F was eradicated by only 0.5 g single dose of zoliflodacin in combination with doxycycline, and WHO X and SE600/18 were both eradicated by a 2 g single dose of zoliflodacin in combination with doxycycline; no zoliflodacin-resistant populations occurred during the 7-day experiment when using this zoliflodacin dose. When using suboptimal (0.5-1 g) zoliflodacin doses together with doxycycline, gonococcal mutants with increased zoliflodacin MICs, due to GyrB D429N and the novel GyrB T472P, emerged, but both the mutants had an impaired biofitness. The present study shows the high efficacy of zoliflodacin plus doxycycline combination therapy using a dynamic HFIM that more accurately and comprehensively simulate gonococcal infection and their treatment, i.e., compared to static in vitro models, such as short-time checkerboard experiments or time-kill curve analysis. Based on our dynamic in vitro HFIM work, zoliflodacin plus doxycycline for the treatment of both gonorrhea and chlamydia can be an effective combination.

Impact of time of culture specimen collection on the recovery of Neisseria gonorrhoeae after a positive nucleic acid amplification test

OBJECTIVES

Culture of Neisseria gonorrhoeae remains essential for antimicrobial resistance (AMR) surveillance. We evaluated the effect of time of specimen collection on culture yield following a positive nucleic acid amplification test (NAAT).

METHODS

We retrospectively assessed N. gonorrhoeae culture yield among asymptomatic individuals (largely men who have sex with men) who attended for sexual health screening and had a positive NAAT. Participants underwent either same-day testing and notification (Drassanes Exprés) or standard screening with deferred testing.

RESULTS

Among 10 423 screened individuals, 809 (7.7%) tested positive for N. gonorrhoeae. A total of 995 different anatomical sites of infection culture was performed in 583 of 995 (58.6%) of anatomical sites (Drassanes Exprés 278 of 347, 80.1%; standard screening 305 of 648, 47.1%; p<0.001). Recovery was highest when culture specimens were collected within 3-7 days of screening with only a slight drop in recovery when the interval extended to 7 days . Recovery from pharynx was 38 of 149 (25.5%) within 3 days, 19 of 81 (23.4%) after 4-7 days (p=0.7245), 11 of 102 (10.7%) after 8-14 days (p<0.0036) and 1 of 22 (4.5%) with longer delays (p=0.00287). Recovery from rectum was 49 of 75 (65.3%) within 3 days, 28 of 45 (62.2%) after 4-7 days (p=0.7318), 41 of 69 (59.4%) after 8-14 days (p=0.4651) and 6 of 18 (33.3%) with longer delays (p=0.0131). Median culture specimen collection time was 1 day within Drassanes Exprés vs 8 days within standard screening. Consequently, the overall culture yield was slightly higher within Drassanes Exprés (102/278, 36.6% vs 99/305, 32.5%; p=0.2934).

CONCLUSION

Reducing the interval between screening and collection of culture specimens increased N. gonorrhoeae recovery in extragenital samples. Implementing a same-day testing and notification programme increased collection of culture samples and culture yield in our setting, which may help AMR surveillance.

Neisseria gonorrhoeae antimicrobial susceptibility trends in Bangkok, Thailand, 2015-21: Enhanced Gonococcal Antimicrobial Surveillance Programme (EGASP)

Objectives

Rising antimicrobial resistance (AMR) in Neisseria gonorrhoeae is a global public health concern. Many ceftriaxone-resistant cases have been linked to Asia. In the WHO/CDC global Enhanced Gonococcal Antimicrobial Surveillance Programme (EGASP), we conducted AMR surveillance at two clinical sites in Bangkok, Thailand, 2015-21.

Methods

Urethral discharge samples, from males with urethral discharge and/or dysuria, were Gram-stained and cultured. ETEST was performed to determine AMR. EGASP MIC alert values, CLSI and EUCAST breakpoints were used.

Results

In 2015-21, gonococcal isolates were cultured from 1928 cases; most (64.1%) were males reporting having sex with females. The sensitivity and specificity of Gram-stained microscopy compared with culture for detection of gonococci were 97.5% and 96.6%, respectively. From 2015 to 2021, the azithromycin MIC90 increased from 0.125 to 1 mg/L, and the MIC90 of ceftriaxone and cefixime increased from 0.008 and ≤0.016 mg/L to 0.032 and 0.064 mg/L, respectively. Eight EGASP MIC alert values (in seven isolates) were identified. Five alert values were for cefixime (all resistant according to EUCAST breakpoints) and three for azithromycin (all resistant according to EUCAST breakpoints). The average annual resistance to ciprofloxacin during 2015-21 was 92%.

Conclusions

A continuous high susceptibility to ceftriaxone, Thailand's first-line gonorrhoea treatment, was found. However, the increasing MICs of ceftriaxone, cefixime and azithromycin are a substantial threat, especially considering these are the last remaining options for the treatment of gonorrhoea. To monitor AMR, continuous and quality-assured gonococcal AMR surveillance such as the Thai WHO/CDC EGASP, ideally including WGS, is imperative globally.

Genome-based epidemiology and antimicrobial resistance of Neisseria gonorrhoeae in Spain: A prospective multicentre study

BACKGROUND

Whole-genome sequencing (WGS) of Neisseria gonorrhoeae isolates combined with epidemiological and phenotypic data provides better understanding of population dynamics.

AIM

The objective of this study was to investigate the molecular epidemiology of N. gonorrhoeae isolates from three centres in Spain and determine associations of antimicrobial resistance.

METHODS

Genetic characterization was performed in 170 N. gonorrhoeae isolates. WGS was carried out with the HiSeq platform (Illumina). Genome assemblies were submitted to the PubMLST Neisseria database website to determine NG-MAST, MLST and NG-STAR. Antimicrobial resistance genes and point mutations were identified with PubMLST. Phylogenomic comparison was based on whole-genome single nucleotide polymorphism analysis.

RESULTS

Twenty-six MLST, 49 NG-MAST and 41 NG-STAR sequence types were detected, the most prevalent being MLST-ST9363 (27.1%), NG-MAST ST569 (12.4%) and NG-STAR ST193 (14.7%). Phylogenetic analysis identified 13 clusters comprising 69% of the isolates, with two of note: one involved cefixime-resistant isolates from Barcelona presenting a mosaic penA X and belonging to MLST-ST7363 and the other involved azithromycin-resistant isolates from Mallorca that possessed the C2611T mutation in the four 23S rRNA alleles belonging to MLST-ST1901.

CONCLUSION

The population of N. gonorrhoeae is quite heterogeneous in Spain. Our results agree with previous data published in Europe, albeit with some differences in distribution between regions. This study describes the circulation of two gonococcal populations with a specific resistance profile and sequence type in a specific geographic area. WGS is an effective tool for epidemiological surveillance of gonococcal infection and detection of resistance genes.

Treatment of bacterial sexually transmitted infections in Europe: gonorrhoea, Mycoplasma genitalium, and syphilis

This review explores the therapeutic challenges of sexually transmitted infections (STI) in Europe, which include increasing antimicrobial resistance and limited progress in drug discovery. We primarily focus on gonorrhoea, Mycoplasma genitalium, and syphilis infections. For gonorrhoea with escalating resistance rates we explore the possibility of combining ceftriaxone with another antibiotic or using alternative antibiotics to mitigate resistance emergence, and we provide insights on the ongoing evaluation of new antimicrobials, like gepotidacin and zoliflodacin. In the case of M. genitalium, which exhibits high resistance rates to first and second-line treatments, we emphasize the importance of resistance-guided therapy in regions with elevated resistance levels, and highlight the limited alternative options, such as pristinamycin and minocycline. Furthermore, we address the challenges posed by syphilis, where the primary treatment consists of penicillin or doxycycline, with challenges arising in neurosyphilis, allergy, pregnancy, and supply shortages and discuss the ongoing evaluation of alternative antimicrobials (e.g., ceftriaxone, cefixime, linezolid). Our findings identify priority actions and provide concrete solutions for long-term effective management of STIs and antimicrobial resistance mitigation.

[Urethritis-spectrum of pathogens, diagnostics and treatment]

A broad spectrum of bacteria, fungi, protozoa and viruses can cause urethritis. In particular, N. gonorrhoeae, C. trachomatis, M. genitalium and T. vaginalis are the focus of diagnostic considerations as classic pathogens associated with sexually transmitted infections (STI). A step-by-step procedure is needed to make a definitive diagnosis. Microscopy with a staining preparation provides an initial differentiation between gonoccocal and non-gonococcal urethritis in symptomatic men as a point-of-care (POC) test. Nucleic acid amplification technology (NAAT) is used for specific and sensitive pathogen detection and, as a multiplex diagnostic test, offers the possibility of detecting several organisms from the same sample. In addition, compared to culture, no vital organisms are required, which allows the collection and use of more diverse and less invasive biological samples (e.g. first stream urine in men or vaginal swabs). Susceptibility testing by culture remains essential for N. gonorrhoeae as resistance is emerging. The treatment of urethritis depends on the suspected or proven pathogen according to the current guidelines. Treatment failure can be caused by many factors (coinfection, lack of therapy adherence, reinfection or resistance of the pathogen) and requires a repeated diagnostic and therapeutic procedure and differentiated approach.

Male Urethritis in Primary Care: Real-World Evidence From a Portuguese Center

Introduction Early diagnosis and treatment of male urethritis are fundamental for preventing complications and further transmission. Primary healthcare services are the first point of contact for patients. This study aimed to assess the practice and compliance of Unidade Saúde Familiar Conde Lousã (USF CL) with best clinical practices. Materials and Methods A retrospective study was undertaken on male urethritis cases at USF CL from January 2018 to March 22, 2021, identified using the International Classification of Primary Care (ICPC) coding system. We established quality criteria encompassing treatment, diagnostics, and reporting. A "sufficiency index" was introduced as a performance metric, which was designed to offer a multiparametric assessment of adherence to these criteria. Results Of 77 cases, 60 were included, averaging 27 years of age. In all, 40.7% showed treatment adequacy, with a sufficiency index of 0.28 for epidemiological characterization and 0.52 for co-infection screening. Prevention measures indexed at 0.28, with 27.1% diagnostic notifications. Conclusion The study reveals gaps in managing male urethritis at USF CL, underscoring the need for standardized guidelines and better diagnostic tools in primary care. Based on these results, a new multicentric specialized sexually transmitted infections clinic was created within our unit in collaboration with a tertiary hospital [Centro Hospitalar Universitário Lisboa Central (CHULC), Lisbon, Portugal] and the national laboratory center [Instituto Nacional de Saúde Doutor Ricardo Jorge (INSA), Lisbon, Portugal].

Effect on the Resistome of Dual vs Monotherapy for the Treatment of Neisseria gonorrhoeae: Results From a Randomized Controlled Trial (ResistAZM Trial)

Background

No randomized controlled trial (RCT) has compared the impact on the resistome of ceftriaxone (CRO) plus azithromycin (AZM) vs CRO for the treatment of Neisseria gonorrhoea (NG).

Methods

This was an open-label, single-center, RCT comparing the effect on the resistome of CRO plus AZM vs CRO for the treatment of NG. Men who have sex with men (MSM) with genital, anorectal, or pharyngeal NG infection were randomized into the CRO/AZM and CRO arms. Oral rinse and anorectal samples were taken for culture and resistome profiling at 2 visits (baseline and day 14). The primary outcome was the ratio of mean macrolide resistance determinants in anorectal samples from day 14 between arms.

Results

Twenty individuals were randomized into the CRO/AZM arm and 22 into the CRO arm. We found no significant difference in the mean macrolide resistance determinants in the day 14 anorectal samples between arms (ratio, 1.05; 95% CI, 0.55-1.83; P = .102). The prevalence of baseline macrolide resistance was high (CRO/AZM arm = 95.00%; CRO arm = 90.91%).

Conclusions

We could not demonstrate a significant effect of dual CRO/AZM therapy on the resistome compared with CRO alone, likely due to a high baseline resistance to AZM. Interventions to prevent the emergence of antimicrobial resistance in MSM are needed.

Antimicrobial Resistance Profiling and Genome Analysis of the penA-60.001 Neisseria gonorrhoeae Clinical Isolates in China in 2021

BACKGROUND

Neisseria gonorrhoeae antimicrobial resistance (AMR) is an urgent public health threat. With dissemination of FC428-related clones, the efficacy of ceftriaxone has become controversial.

METHODS

Agar dilution and whole genome sequencing were used to analyze AMR.

RESULTS

High resistance to penicillin (75.2%), tetracycline (87.9%), ciprofloxacin (98.3%), ceftriaxone (8.9%), cefixime (14.3%), and azithromycin (8.6%) was observed among 463 isolates first collected in China in 2021. All penA-60.001 clones exhibited resistance to ceftriaxone or cefixime, and 1 of the 12 cases was resistant to azithromycin. ngMAST and ngSTAR of penA-60.001 isolates showed that single-nucleotide polymorphisms in the porB, tbpB, ponA, gyrA, and parC genes were the major causes of different sequence types. MLST-7365 (n = 5) and MLST-1903 (n = 3) were main genotypes, and the other 4 strains featured MLST-10314, MLST-13871, MLST-7827 and MLST-1600. Furthermore, resistance markers (eg, penA, blaTEM-1, blaTEM-135) and virus factors were detected. Most penA-60.001 strains were fully mixed with global FC428-related clones; 2021-A2 and F89 had the same origin; and 2021-A1 exhibited a unique evolutionary trajectory.

CONCLUSIONS

Results provide the first demonstration of extremely severe AMR rates of N gonorrhoeae in China in 2021, particularly strains with ceftriaxone decreased susceptibility. The sustained transmission of penA-60.001 subclones might further threaten treatment effectiveness.

Sustained Transmission of Neisseria gonorrhoeae Strains with High-Level Azithromycin Resistance (MIC ≥ 256 μg/mL) in Argentina, 2018 to 2022

Azithromycin combined with ceftriaxone is the recommended dual therapy for uncomplicated gonorrhea in many countries. Nevertheless, the increasing prevalence of azithromycin resistance compromises the effectiveness of this treatment strategy. From 2018 to 2022, we collected 13 gonococcal isolates with high-level azithromycin resistance (MIC ≥ 256 μg/mL) across Argentina. Whole-genome sequencing revealed that these isolates were mainly represented by the internationally spreading Neisseria gonorrhoeae multi-antigen sequence typing (NG-MAST) genogroup G12302, containing the 23S rRNA A2059G mutation (in all four alleles) together with mosaic mtrD and mtrR promoter 2 loci. This information is important to develop targeted public health policies to control the spread of azithromycin-resistant N. gonorrhoeae in Argentina and internationally. IMPORTANCE Azithromycin resistance in Neisseria gonorrhoeae has been increasing in numerous populations worldwide, which is of concern, as azithromycin is part of the recommended dual treatment in many countries. Here, we report 13 N. gonorrhoeae isolates with high-level azithromycin resistance (MIC ≥ 256 μg/mL). This study observed that high-level azithromycin-resistant gonococcal strains have shown sustained transmission in Argentina and are related to the successful international clone NG-MAST G12302. Genomic surveillance together with real-time tracing and data-sharing networks will be crucial in controlling the spread of azithromycin resistance in gonococcus.

Chlamydial and Gonococcal Genital Infections: A Narrative Review

Sexually transmitted infections (STIs) constitute one of the leading causes of disease burden worldwide, leading to considerable morbidity, mortality, health expenditures, and stigma. Of note are the most common bacterial STIs, chlamydial and gonococcal infections, whose etiological agents are Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG), respectively. Despite being usually asymptomatic, in some cases these infections can be associated with long-term severe complications, such as pelvic inflammatory disease, chronic pelvic pain, infertility, ectopic pregnancy, and increased risk of other STIs acquisition. As the symptoms, when present, are usually similar in both infections, and in most of the cases these infections co-occur, the dual-test strategy, searching for both pathogens, should be preferred. In line with this, herein we focus on the main aspects of CT and NG infections, the clinical symptoms as well as the appropriate state-of-the-art diagnostic tests and treatment. Cost-effective strategies for controlling CT and NG infections worldwide are addressed. The treatment for both infections is based on antibiotics. However, the continuing global rise in the incidence of these infections, concomitantly with the increased risk of antibiotics resistance, leads to difficulties in their control, particularly in the case of NG infections. We also discuss the potential mechanism of tumorigenesis related to CT infections. The molecular bases of CT and NG infections are addressed, as they should provide clues for control or eradication, through the development of new drugs and/or effective vaccines against these pathogens.

High-level in vitro resistance to gentamicin acquired in a stepwise manner in Neisseria gonorrhoeae

OBJECTIVES

Gentamicin is used in several alternative treatments for gonorrhoea. Verified clinical Neisseria gonorrhoeae isolates with gentamicin resistance are mainly lacking and understanding the mechanisms for gonococcal gentamicin resistance is imperative. We selected gentamicin resistance in gonococci in vitro, identified the novel gentamicin-resistance mutations, and examined the biofitness of a high-level gentamicin-resistant mutant.

METHODS

Low- and high-level gentamicin resistance was selected in WHO X (gentamicin MIC = 4 mg/L) on gentamicin-gradient agar plates. Selected mutants were whole-genome sequenced. Potential gentamicin-resistance fusA mutations were transformed into WT strains to verify their impact on gentamicin MICs. The biofitness of high-level gentamicin-resistant mutants was examined using a competitive assay in a hollow-fibre infection model.

RESULTS

WHO X mutants with gentamicin MICs of up to 128 mg/L were selected. Primarily selected fusA mutations were further investigated, and fusAR635L and fusAM520I + R635L were particularly interesting. Different mutations in fusA and ubiM were found in low-level gentamicin-resistant mutants, while fusAM520I was associated with high-level gentamicin resistance. Protein structure predictions showed that fusAM520I is located in domain IV of the elongation factor-G (EF-G). The high-level gentamicin-resistant WHO X mutant was outcompeted by the gentamicin-susceptible WHO X parental strain, suggesting lower biofitness.

CONCLUSIONS

We describe the first high-level gentamicin-resistant gonococcal isolate (MIC = 128 mg/L), which was selected in vitro through experimental evolution. The most substantial increases of the gentamicin MICs were caused by mutations in fusA (G1560A and G1904T encoding EF-G M520I and R635L, respectively) and ubiM (D186N). The high-level gentamicin-resistant N. gonorrhoeae mutant showed impaired biofitness.

Antimicrobial susceptibility assays for Neisseria gonorrhoeae: a proof-of-principle population-based retrospective analysis

BACKGROUND

Neisseria gonorrhoeae treatment guided by molecular antimicrobial susceptibility assays could improve treatment options and antimicrobial stewardship; however, few commercial assays are available. We aimed to investigate antimicrobial susceptibility of N gonorrhoeae isolates in New South Wales, Australia, and estimate the potential usefulness of hypothetical combinations of rapid molecular antimicrobial susceptibility assays.

METHODS

In this proof-of-principle, population-based, retrospective analysis, we assessed N gonorrhoeae susceptibility data for ceftriaxone, azithromycin, ciprofloxacin, and penicillin. Isolates were previously collected as part of the Australian Gonococcal Surveillance Programme between Jan 1, 2008, and Dec 31, 2019. All cultured N gonorrhoeae isolates with susceptibility data to all four antimicrobials were included. However, only one isolate was included if several isolates originated from the same individual within 13 days of the previous isolate originating from that individual, and there were less than two standard double-dilution minimum inhibitory concentrations between the isolates. We assessed the use of different combinations of hypothetical antimicrobial susceptibility assays and treatment combinations in terms of their ability to minimise overall ceftriaxone use, and use specifically in isolates with decreased susceptibility to ceftriaxone, compared with standard non-assay-guided empirical ceftriaxone treatment.

FINDINGS

We included 23 089 N gonorrhoeae isolates. The prevalence of antimicrobial sensitivity fluctuated significantly during the study. Isolates with decreased susceptibility to ceftriaxone were more likely to be resistant to one or more antimicrobials than isolates without decreased susceptibility (782 [98·6%] of 793 vs 10 661 [47·8%] of 22 296), particularly ciprofloxacin (p<0·0001) and penicillin (p<0·0001). Compared with empirical ceftriaxone treatment, we estimated that strategies based on the use of hypothetical antimicrobial susceptibility would reduce ceftriaxone use (p<0·0001). However, because of co-resistance, most assay-directed treatment strategies, including those involving use of assays for two antibiotics, would result in only moderate reductions in ceftriaxone use among isolates with decreased susceptibility to ceftriaxone.

INTERPRETATION

Individualised treatment guided by molecular antimicrobial susceptibility diagnostics could help to reduce overall ceftriaxone use in gonorrhoea. However, the use of these assays needs to be informed by the non-random nature of co-resistance among circulating N gonorrhoeae strains.

FUNDING

Australian Government and Queensland Government.

Alarming incidence of reinfections after treatment for Chlamydia trachomatis and gonorrhoea: Can we predict and prevent them?

BACKGROUND

Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infections are a public health problem, worsened by frequent reinfections, whose incidence rate is not known in Spain. The objective of this study is to estimate in patients diagnosed with NG, CT or mixed infection (NG and CT): (1) the incidence of reinfections by the same microorganism, (2) the total incidence of Sexually Transmitted Infections (STI), both by the same microorganism and by infections other than the initial one, and (3) to identify predictors of reinfection.

METHODS

Observational prospective case series involving 986 patients with CT and/or NG at specialized STI clinics in Biscay (Spain) between 2016 and 2019.

RESULTS

The six month cumulative incidence of reinfection by the same microorganism was 17.24% (CI95%: 14.9-19.7) and 24.65% (CI95%: 21.9-27.4) for any STI (reinfection or other). Being an immigrant (OR=1.8; CI95%: 1.3-2.6), men who have sex with men (OR=1.8; CI95%: 1.3-2.6), number of sexual partners (OR=4.3; CI95%: 2.7-6.8 for more than 5 partners), having a new partner (OR=1.7; CI95%: 1.08-2.6), not always using a condom (OR=1.4; CI95%: 1.02-1.9) and consumption of alcohol prior to sex (OR=3.8; CI95%: 1.5-9.5) were associated with reinfection by any STI.

CONCLUSION

These characteristics allow doctors to identify patients in whom to prioritize short-term rescreening for repeated infections with any STIs after initial treatment for NG or CT.

Effect of food on the pharmacokinetics of zoliflodacin granules for oral suspension: Phase I open-label randomized cross-over study in healthy subjects

Gonorrhea is a sexually transmitted infection for which antibiotic treatment options have declined due to increasing antibiotic resistance. Zoliflodacin, an investigational oral spiropyrimidinetrione antibiotic with activity against Neisseria gonorrhoeae strains that are multidrug-resistant, including to third-generation cephalosporins, is in phase III development for uncomplicated gonorrhea. This phase I, parallel, open-label, randomized, crossover study in healthy adults evaluated the effect of food on the pharmacokinetics of single 3 or 4 g doses of zoliflodacin administered as granules for oral suspension in the fasted state or after consumption of a standardized high-fat meal. Forty-seven out of 48 randomized subjects completed the study. Oral administration of zoliflodacin with food delayed the absorption rate, compared with fasted state, with time to maximum concentration (T_max ) increasing from 3 to 6 h for the 3 g dose, and 2.5 to 4 h for the 4 g dose, but had no impact on the elimination of zoliflodacin. The maximum concentration (C_max ) and area under the plasma concentration-time curve from time 0 to 24 h (AUC_(0-24) ) significantly increased with food by 52% and 94% for the 3 g dose, and by 89% and 108% for the 4 g dose. Forty-two percent of participants reported a total of 34 treatment-emergent adverse events (TEAEs), which were all considered mild in severity. Headache was the most common TEAE (22/48 subjects, 45.8%) and the only TEAE reported in more than one subject. In conclusion, administration of single 3 and 4 g doses of zoliflodacin as granules for oral suspension, with a high-fat meal was well-tolerated and resulted in statistically significant increases in peak and overall systemic exposure to zoliflodacin.

Prior Exposure to Azithromycin and Azithromycin Resistance Among Persons Diagnosed With Neisseria gonorrhoeae Infection at a Sexual Health Clinic: 2012-2019

BACKGROUND

There is conflicting evidence on whether prior azithromycin (AZM) exposure is associated with reduced susceptibility to AZM (AZMRS) among persons infected with Neisseria gonorrhoeae (NG).

METHODS

The study population included Public Health-Seattle and King County Sexual Health Clinic (SHC) patients with culture-positive NG infection at ≥1 anatomic site whose isolates were tested for AZM susceptibility in 2012-2019. We used multivariate logistic regression to examine the association of time since last AZM prescription from the SHC in ≤12 months with subsequent diagnosis with AZMRS NG (minimum inhibitory concentration [MIC], ≥2.0 µg/mL) and used linear regression to assess the association between the number of AZM prescriptions in ≤12 months and AZM MIC level, controlling for demographic, behavioral, and clinical characteristics.

RESULTS

A total of 2155 unique patients had 2828 incident NG infections, 156 (6%) of which were caused by AZMRS NG. AZMRS NG was strongly associated with receipt of AZM from the SHC in the prior 29 days (adjusted odds ratio, 6.76; 95% confidence interval [CI], 1.76 to 25.90) but not with receipt of AZM in the prior 30-365 days. Log AZM MIC level was not associated with the number of AZM prescriptions within ≤12 months (adjusted correlation, 0.0004; 95% CI, -.04 to .037) but was associated with number of prescriptions within <30 days (adjusted coefficient, 0.56; 95% CI, .13 to .98).

CONCLUSIONS

Recent individual-level AZM treatment is associated with subsequent AZMRS gonococcal infections. The long half-life and persistence of subtherapeutic levels of AZM may result in selection of resistant NG strains in persons with recent AZM use.

Andueza Lillo J, Sanjurjo-Sáez M. Appropriateness of Empirical Antibiotic Therapy for Cervicitis and Urethritis Prescribed in the Emergency Department

Objectives

Sexually transmitted infections are a prevalent global health care problem. Treatment guidelines have recently been updated as a result of antimicrobial resistance and public health trends. The aim of the study was to assess the appropriateness of empirical antibiotic therapy prescribed for cervicitis and urethritis in the emergency department.

Methods

We designed a retrospective observational cohort study. We included adult patients with suspected cervicitis or urethritis who attended the emergency department of a tertiary hospital in 2020. We excluded patients with suspected pelvic inflammatory disease, pregnancy or prostatitis and those requiring admission to hospital. Appropriateness of empirical antibiotic therapy was evaluated taking into account 4 aspects: indication, dosing, duration of therapy, and route of administration. Data were obtained from the electronic medical record, the electronic prescription program, and the discharge summary.

Results

The study population comprised 176 patients; mean age was 28.9 years (SD = 7.7), and 90.9% were men. The most prescribed treatment was the combination of ceftriaxone and azithromycin (83.0%). Treatment was inappropriate in 71.6% of patients. A total of 159 drug errors were recorded. The most frequent cause was undertreatment (36.4%) related to underdosing (46.5%), particularly with regard to ceftriaxone. The percentage of errors was 11.9% for indication, 84.9% for dosing, 3.1% for duration, and 0% for route of administration.

Conclusions

A high percentage of patients who attended the emergency department for suspected cervicitis or urethritis received an inappropriate empirical antibiotic regimen. The main reason was undertreatment due to underdosing.

Azithromycin Susceptibility Testing and Molecular Investigation of Neisseria gonorrhoeae Isolates Collected in Russia, 2020-2021

The aim of this work was to study the resistance to macrolides (azithromycin) in the modern Russian population of N. gonorrhoeae with the analysis of genetic resistance determinants. Azithromycin is not used to treat gonococcal infection in Russia. However, among 162 isolates collected in 2020-2021, 22 isolates (13.6%) were phenotypically resistant to azithromycin. Mutations in 23S rRNA genes were found only in two isolates; erm and mefA genes were absent. Azithromycin resistance was shown to be predominantly associated with mutations in the mtrR and mtrD genes of the MtrCDE efflux pump and their mosaic alleles which may have formed due to a horizontal transfer from N. meningitidis. A total of 30 types of mtrR alleles and 10 types of mtrD alleles were identified including mosaic variants. Matching between the mtrR and mtrD alleles was revealed to indicate the cooperative molecular evolution of these genes. A link between the mtrR and mtrD alleles and NG-MAST types was found only for NG-MAST 228 and 807, typical of N. gonorrhoeae in Russia. The high level of resistance to azithromycin in Russia may be related to the spread of multiple transferable resistance to antimicrobials regardless of their use in the treatment of gonococcal infection.

[Urethritis due to coinfection with Neisseria gonorrhoeae and Enterobius vermicularis in a 27-year-old man]

Urethritis is mainly caused by sexually transmitted pathogens, such as Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) [1]. Close to 90 million adults are infected annually with NG [2]. Treatment shall be performed according to national guidelines and resistance profiles [2, 3]. Enterobius vermicularis (EV) is the most common helminth in humans with 1 billion people globally infected [4-6]. Symptoms include anal pruritus; however, many infections are asymptomatic [4-7]. A case of urethritis due to simultaneous infection with NG and EV is reported.

Antimicrobial susceptibility surveillance and antimicrobial resistance in Neisseria gonorrhoeae in Africa from 2001 to 2020: A mini-review

Antimicrobial resistance (AMR) in Neisseria gonorrhoeae (NG), compromising gonorrhea treatment, is a global public health concern. Improved, quality-assured NG AMR monitoring at the global level is essential. This mini-review examined NG AMR susceptibility surveillance and AMR data from the African continent from 2001 to 2020. Eligible peer-reviewed publications (n = 30) containing NG AMR data for antimicrobials currently recommended for gonorrhea treatment were included. Overall, very limited NG surveillance and AMR data was available. Furthermore, the NG AMR surveillance studies varied greatly regarding surveillance protocols (e.g., populations and samples tested, sample size, antimicrobials examined), methodologies (e.g., antimicrobial susceptibility testing method [agar dilution, minimum inhibitory concentration (MIC) gradient strip test, disc diffusion test] and interpretative criteria), and quality assurance (internal quality controls, external quality assessments [EQA], and verification of AMR detected). Moreover, most studies examined a suboptimal number of NG isolates, i.e., less than the WHO Global Gonococcal Antimicrobial Surveillance Program (GASP) and WHO Enhanced GASP (EGASP) recommendations of ≥100 isolates per setting and year. The notable inter-study variability and frequently small sample sizes make appropriate inter-study and inter-country comparisons of AMR data difficult. In conclusion, it is imperative to establish an enhanced, standardized and quality-assured NG AMR surveillance, ideally including patient metadata and genome sequencing as in WHO EGASP, in Africa, the region with the highest gonorrhea incidence globally. This will enable the monitoring of AMR trends, detection of emerging AMR, and timely refinements of national and international gonorrhea treatment guidelines. To achieve this aim, national and international leadership, political and financial commitments are imperative.

Optimisation of treatments for oral Neisseria gonorrhoeae infection: Pharmacokinetics Study (STI-PK project) - study protocol for non-randomised clinical trial

INTRODUCTION

Neisseria gonorrhoeae infections are common and incidence increasing. Oropharyngeal infections are associated with greater treatment failure compared with other sites and drive transmission to anogenital sites through saliva. Gonococcal resistance is increasing and new treatments are scarce, therefore, clinicians must optimise currently available and emerging treatments in order to have efficacious therapeutic options. This requires pharmacokinetic data from the oral cavity/oropharynx, however, availability of such information is currently limited.

METHODS AND ANALYSIS

Healthy male volunteers (participants) recruited into the study will receive single doses of either ceftriaxone 1 g, cefixime 400 mg or ceftriaxone 500 mg plus 2 g azithromycin. Participants will provide samples at 6-8 time points (treatment regimen dependent) from four oral sites, two oral fluids, one anorectal swab and blood. Participants will complete online questionnaires about their medical history, sexual practices and any side effects experienced up to days 5-7. Saliva/oral mucosal pH and oral microbiome analysis will be undertaken. Bioanalysis will be conducted by liquid chromatography-mass spectrometry. Drug concentrations over time will be used to develop mathematical models for optimisation of drug dosing regimens and to estimate pharmacodynamic targets of efficacy.

ETHICS AND DISSEMINATION

This study was approved by Royal Melbourne Hospital Human Research Ethics Committee (60370/MH-2021). The study results will be submitted for publication in peer-reviewed journals and reported at conferences. Summary results will be sent to participants requesting them. All data relevant to the study will be included in the article or uploaded as supplementary information.

TRIAL REGISTRATION NUMBER

ACTRN12621000339853.

Resistance profiles of Neisseria gonorrhoeae isolates in Vienna, Austria: a phenotypic and genetic characterization from 2013 to 2020

OBJECTIVES

International surveillance data show a constant rise in the number of Neisseria gonorrhoeae infections and an increase in drug resistance of N. gonorrhoeae. As recent N. gonorrhoeae surveillance data in Austria are scarce, this study investigated phenotypic and genotypic antimicrobial resistance in N. gonorrhoeae isolates.

METHODS

In total, 440 N. gonorrhoeae samples were collected at the Medical University of Vienna, and the minimal inhibitory concentrations (MICs) for a range of different antibiotics were determined. Sampling sites and treatments were recorded, and whole-genome sequencing of N. gonorrhoeae isolates was performed using allele libraries to determine genotypic resistance.

RESULTS

The median MICs for ceftriaxone, cefixime, azithromycin, ciprofloxacin, tetracycline and penicillin were <0.002 µg/mL, <0.016 µg/mL, 0.25 µg/mL, 2.0 µg/mL, 1.5 µg/mL and 0.25 µg/mL, respectively. Annual comparison showed that MICs were generally stable for all antimicrobial agents except azithromycin, for which an increase in median MIC was observed from 2017 (0.25 µg/mL). There was no genetic resistance to ceftriaxone; 8% of samples displayed resistance mutations against cefixime, primarily located in the penA gene. Resistance to azithromycin increased from 2% in 2013 to 12% in 2020. MtrD mosaic had the highest impact on azithromycin susceptibility; 47% of the resistant isolates showed this mutation. The majority of cases of gonorrhoea were treated successfully with either ceftriaxone or a ceftriaxone/azithromycin regime. Two treatment failures occurred under monotherapy with doxycycline. Overall, genotypic resistance corresponded significantly to all respective MICs.

CONCLUSIONS

The resistance rate of N. gonorrhoeae to antibiotics has remained stable in Vienna over the last decade, except for azithromycin. The strong correlation found between genetic and phenotypic patterns in this study holds promise for future diagnostics of N. gonorrhoeae resistance based on genotypes.

Potent In Vitro and Ex Vivo Anti-Gonococcal Activity of the RpoB Inhibitor Corallopyronin A

Gonorrhea remains a major global public health problem because of the high incidence of infection (estimated 82 million cases in 2020) and the emergence and spread of Neisseria gonorrhoeae strains resistant to previous and current antibiotics used to treat infections. Given the dearth of new antibiotics that are likely to enter clinical practice in the near future, there is concern that cases of untreatable gonorrhea might emerge. In response to this crisis, the World Health Organization (WHO), in partnership with the Global Antibiotic Research and Development Partnership (GARDP), has made the search for and development of new antibiotics against N. gonorrhoeae a priority. Ideally, these antibiotics should also be active against other sexually transmitted organisms, such as Chlamydia trachomatis and/or Mycoplasma genitalium, which are often found with N. gonorrhoeae as co-infections. Corallopyronin A is a potent antimicrobial that exhibits activity against Chlamydia spp. and inhibits transcription by binding to the RpoB switch region. Accordingly, we tested the effectiveness of corallopyronin A against N. gonorrhoeae. We also examined the mutation frequency and modes of potential resistance against corallopyronin A. We report that corallopyronin A has potent antimicrobial action against antibiotic-susceptible and antibiotic-resistant N. gonorrhoeae strains and could eradicate gonococcal infection of cultured, primary human cervical epithelial cells. Critically, we found that spontaneous corallopyronin A-resistant mutants of N. gonorrhoeae are exceedingly rare (≤10^-10) when selected at 4× the MIC. Our results support pre-clinical studies aimed at developing corallopyronin A for gonorrheal treatment regimens. IMPORTANCE The high global incidence of gonorrhea, the lack of a protective vaccine, and the emergence of N. gonorrhoeae strains expressing resistance to currently used antibiotics demand that new treatment options be developed. Accordingly, we investigated whether corallopyronin A, an antibiotic which is effective against other pathogens, including C. trachomatis, which together with gonococci frequently cause co-infections in humans, could exert anti-gonococcal action in vitro and ex vivo, and potential resistance emergence. We propose that corallopyronin A be considered a potential future treatment option for gonorrhea because of its potent activity, low resistance development, and recent advances in scalable production.

Diagnosis of Neisseria Gonorrhoeae by Loop-Mediated Isothermal Amplification: Systematic Review and Meta-Analysis

Neisseria gonorrhoeae (gonococci) is the pathogen of gonorrhea. At present, there is no robust statistical analysis targeting the detection accuracy for N.gonorrhoeae of loop-mediated isothermal amplification (LAMP). We performed a full search of five databases for studies using the LAMP method to detect N.gonorrhoeae in this study. Nine datasets derived from eight studies satisfying the inclusion requirement were collected for this study. The pooled sensitivity rate and specificity were calculated as 98.53 and 99.49%. The pooled positive likelihood ratio (PLR), negative likelihood ratio (NLR) and diagnostic odds ratio (DOR) were 66.0, 0.04 and 1863.8. After plotting the summary receiver operating characteristic (sROC), the area under the curve (AUC) and Q* index was calculated as 0.99 and 0.9774. Subgroup analyses based on the type of samples, location, and gold standard did not find sources of significant heterogeneity. In conclusion, the LAMP method could be an effective and convenient method with high accuracy for the clinical detection of N.gonorrhoeae. Moreover, the confirmation of this finding needs more high-quality studies with regional data and large samples.

Sexually transmitted pathogens causing urethritis: A mini-review and proposal of a clinically based diagnostic and therapeutic algorithm

The purpose of this mini-review was to provide the latest information and concepts on diagnosis and treatment of the most common sexually transmitted pathogens causing urethritis. The incidence of several sexually transmitted infections that cause urethritis is increasing, and this genitourinary syndrome is among the most common reason young men see clinical care. The authors performed a literature search including the currently valid guidelines, and an overview of the most relevant pathogens is given. Moreover, the authors developed a clinically applicable diagnostic and therapeutic algorithm, because early diagnosis and correct treatment can sometimes prevent infected individuals from significant morbidity. Future research will focus on new methods to combat pathogens that cause urethritis, including vaccination.

In Vitro Study of the Interaction of Gentamicin with Ceftriaxone and Azithromycin against Neisseria gonorrhoeae Using Agar Dilution Method

The susceptibility to gentamicin of N. gonorrhoeae isolates collected in three Chinese provinces and the correlation among the MICs of gentamicin, azithromycin, and ceftriaxone were investigated in this study. The effects of combinations from those three antibiotics were also in the scope of this study to determine the efficacy of gentamicin as a combination therapeutic drug. The agar dilution method was used to measure the minimum inhibitory concentrations (MICs) of ceftriaxone, azithromycin and gentamicin on N. gonorrhoeae isolates. The synergy between these three antimicrobials were determined using the agar dilution checkerboard method. Subgroup studies were conducted to explore differences between azithromycin- and ceftriaxone-sensitive and resistant isolates. A total of 139 (36.60%) and 233 (61.30%) isolates demonstrated full susceptibility and intermediate susceptibility to gentamicin, respectively. The correlation analysis showed that the MICs of ceftriaxone and azithromycin weakly correlated with the value of gentamicin. The overall results of the three antibiotic combinations revealed indifferent effects. Combination therapy established a significant reduction on the MIC value. Most of the N. gonorrhoeae isolates tested in this study demonstrated a certain degree of susceptibility to gentamicin. Overall, antimicrobial combinations of gentamicin with ceftriaxone or azithromycin demonstrate indifferent effects.

Genomic surveillance and antimicrobial resistance in Neisseria gonorrhoeae isolates in Bangkok, Thailand in 2018

OBJECTIVES

Antimicrobial resistance (AMR) in Neisseria gonorrhoeae is a substantial global public health problem. Gonococcal infections acquired in or from Asia represent most verified ceftriaxone treatment failures, and several ceftriaxone-resistant strains have emerged in Asia and subsequently spread globally. Additionally, in Thailand the gonorrhoea incidence remains high. Herein, we investigate the genomic diversity, AMR and AMR determinants in gonococcal isolates cultured in 2018 in Bangkok, Thailand.

METHODS

Gonococcal isolates from males (n = 37) and females (n = 62) were examined by Etest and WGS. AMR determinants and molecular epidemiological STs were characterized. For phylogenomic comparison, raw sequence data were included from China (432 isolates), Japan (n = 270), Vietnam (n = 229), Thailand (n = 3), a global dataset (n = 12 440) and the 2016 WHO reference strains plus WHO Q (n = 15).

RESULTS

In total, 88, 66 and 41 different NG-MAST, NG-STAR and MLST STs, respectively, and 31 different NG-STAR clonal complexes were found. A remarkably high frequency (88%) of β-lactamase TEM genes was detected and two novel TEM alleles were found. The phylogenomic analysis divided the isolates into the previously described lineages A and B, with a large proportion of Thai isolates belonging to the novel sublineage A3.

CONCLUSIONS

We describe the first molecular epidemiological study using WGS on gonococcal isolates from Thailand. The high prevalence of AMR and AMR determinants for ciprofloxacin, tetracycline and benzylpenicillin, and some strains belonging to clones/clades especially in sublineage A2 that are prone to develop resistance to extended-spectrum cephalosporins (ESCs) and azithromycin, should prompt continued and strengthened AMR surveillance, including WGS, of N. gonorrhoeae in Thailand.

In vitro selection of Neisseria gonorrhoeae unveils novel mutations associated with extended-spectrum cephalosporin resistance

The emergence of Neisseria gonorrhoeae strains resistant to extended-spectrum cephalosporins (ESCs) is a worldwide concern because this class of antibiotics represents the last empirical treatment option for gonorrhea. The abusive use of antimicrobials may be an essential factor for the emergence of ESC resistance in N. gonorrhoeae. Cephalosporin resistance mechanisms have not been fully clarified. In this study, we mapped mutations in the genome of N. gonorrhoeae isolates after resistance induction with cefixime and explored related metabolic pathways. Six clinical isolates with different antimicrobial susceptibility profiles and genotypes and two gonococcal reference strains (WHO F and WHO Y) were induced with increasing concentrations of cefixime. Antimicrobial susceptibility testing was performed against six antimicrobial agents before and after induction. Clinical isolates were whole-genome sequenced before and after induction, whereas reference strains were sequenced after induction only. Cefixime resistance induction was completed after 138 subcultures. Several metabolic pathways were affected by resistance induction. Five isolates showed SNPs in PBP2. The isolates M111 and M128 (ST1407 with mosaic penA-34.001) acquired one and four novel missense mutations in PBP2, respectively. These isolates exhibited the highest minimum inhibitory concentration (MIC) for cefixime among all clinical isolates. Mutations in genes contributing to ESC resistance and in other genes were also observed. Interestingly, M107 and M110 (ST338) showed no mutations in key determinants of ESC resistance despite having a 127-fold increase in the MIC of cefixime. These findings point to the existence of different mechanisms of acquisition of ESC resistance induced by cefixime exposure. Furthermore, the results reinforce the importance of the gonococcal antimicrobial resistance surveillance program in Brazil, given the changes in treatment protocols made in 2017 and the nationwide prevalence of sequence types that can develop resistance to ESC.

Antimicrobial resistance of <i>Neisseria gonorrhoeae</i> and gonococcal infection therapy: yesterday, today, tomorrow

Implementation of the Russian version of Gonococcal Antimicrobial Surveillance Programme (RU-GASP) in XXI century is summarized. The chronology of evidence-based updating of national clinical guidelines for the gonococcal infection management is outlined. The reasons for penicillins, tetracyclines, and fluoroquinolones excluding from gonococcal infection treatment regimens is presented, and the dynamics of subsequent changes in the sensitivity of N. gonorrhoeae to these antimicrobials is described. The modern schemes of monotherapy of gonococcal infection with third generation cephalosporins and the chronology of increasing their recommended doses are presented. The spectinomycin indications and restrictions for alternative treatment of the gonococcal infection are characterized. The absence of azithromycin in Russian gonococcal infection guideline versus international experience of this antibiotic usage is discussed. Based on current data on the ongoing spread of antimicrobial resistance genetic determinants in N. gonorrhoeae, proposals have been made to improve the RU-GASP protocols and to select drugs for the modern gonococcal infection etiotropic therapy.

Neisseria gonorrhoeae culture growth rates from asymptomatic individuals with a positive nucleic acid amplification test

Gonorrhoea infections are frequently diagnosed at extragenital locations in asymptomatic individuals and are historically related to poor recovery in culture, which hinders antimicrobial susceptibility testing. The aim of this study was to evaluate recovery rates of N. gonorrhoeae by culture among asymptomatic individuals who tested positive by nucleic acid amplification tests between 2018 and 2019 in Barcelona (Spain). In total, 10,396 individuals were tested for N. gonorrhoeae on first-void urine, rectal, pharyngeal, and/or vaginal swabs depending on sexual behaviour. Overall infection prevalence was 5.5% (95% confidence interval [CI] 5.0 to 5.9%). Seven hundred and ten samples were positive corresponding to 567 individuals. The most common site of infection was the pharynx (71.3%), followed by rectum (23.1%) and genitals (4.7%) (p<0.0001). The N. gonorrhoeae recovery rate in culture, time from positive screening to culture specimen, and inoculation delay were calculated. Recovery rate was 21.7% in pharynx, 66.9% in rectum, and 37.0% in genitals (25.0% vagina, 71.4% urethra) (p<0.0001). Median culture collection time was 1 [0; 3] days, and median inoculation delay was 5.01 [4.99-7.99] hours, with no impact on N. gonorrhoeae recovery, p=0.8367 and p=0.7670, respectively. Despite efforts towards optimizing pre-analytical conditions, the N. gonorrhoeae recovery rate in asymptomatic individuals is unacceptably low (especially for pharynx), representing a problem for monitoring antimicrobial-resistant infections.